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Hi

If you got $300 or so available just go buy a yaesu 450 rotator.. job done, safe, looks good (Wife and Landlord friendly.) reliable and holds resale value.

Have one here holding up tein 2m tagi’s and 10m yagi.. year old, looks as new and on Dartmoor so very open to high winds and rain ( and sun.)

Job done, forget about, especially if you up high on balcony, last thing one needs is an antenna hanging from cable over someone’s head! $300 ( or so, mine i had buy bottom clamps.) well spent.

Simon g0zen

This whole discussion makes me think that maybe double boxing is the
easiest way to go :)

On Wed, Aug 21, 2024 at 3:10?PM wn4isx via groups.io
<wn4isx@...> wrote:

On Mon, Aug 19, 2024 at 02:35 PM, Alan wrote:

epoxy

I'm still researching ways the big boys in high tech protect their electronics, this site doesn't quite qualify as big boys but is interesting.

This one photograph was both telling and a bit frightening because I'd come extremely close to using epoxy.
OK I can't copy the link without the photo coming up, look for a photo with pealed back epoxy.

I use conformal silicon spray and have for the last 15 years (or so) Even in cases with severe condensation, the boards were unharmed, the connectors though rotted out from the inside.

I'm not sure non-milspec conformal spray silicon is UV resistant, the jury is still out on that question.
My remote Geiger counter is a standard Budd box with the lid that has lips that go down inside the other case. I drenched the unit in spray silicon conformal spray because the GM tube has a 400V power supply on a G10 bit of circuit board. The board was also coated in conformal spray.

Yeah, I used unistruts/superstruts for some of my other projects...
Looks like he got quite a bit of a setup. I'm trying to avoid that.
Maybe I just look into other more heavy duty rotators. Thank you for
all this information!
Regards,
Simon

On Wed, Aug 21, 2024 at 4:59?AM wn4isx via groups.io
<wn4isx@...> wrote:

He used PVC pipe cut lengthwise with hose clamps to compress the PVC for a "sort of snug fit." lubricated with silicon grease and fabricated an "umbrella" with a hole in it to keep out water. This was to keep the grease from washing out and to prevent rain water ingress that would lock things when the temps dropped below freezing. It is butt ugly but works.

There are a variety of vertical support and cross members that'd work.

The "Allied Tube & Conduit 10-ft 12-Gauge Electro-galvanized Slotted Channel Strut" Is called uni-strut as a generic name by electricians and several different companies make similar or identical material. The advantage of this stuff is they make specialized nuts that make assembly a breeze. The material is also heavily galvanized so it should last at least a decade before rust is an issue.



The strut material is a bit pricy. One could use treated wood if they dug post holes, or galvanized pipe, I suspect 1" steel pipe would be strong enough.

The strut material's shape adds to the stability of the buried section.

I've seen commercial utility electric service entrance (tech speak for meter box) mounted "struts" that I know have been there for at least 30+ years. The Goodwill I "mine" once a month or so went in in the late 1980s and their service entrance is mounted on "struts.







Note: One must be careful to not allow any DC to flow through the "Slotted Channel Strut" because that can strip off the zinc.

If any negative DC current does flow, one must counter it by biasing the struts positive.

The telephone company (when they used copper) used positive ground so electrolysis would deposit minerals on exposed wires and not reverse electro-plate the copper away.

Positive current will cause the strut to rot away.

What would you recommend that's easy to apply? I can re-apply it once
in half a year or so. Not really expecting it to last 25 years.

I'm afraid I don't have any ideas outside of MILSPEC conformal coatings, or embedding in epoxy, and even then, equipment is usually inside something else that takes the brunt of damaging conditions, the coating or potting generally being a backup plan in case of exposure.

I have not tried to re-apply a coating over a coating.

Maybe double cases would help?

I use UV stabilized plastic boxes in rare instances, but generally use aluminum, steel, or "white metal" cases.

Plastic has proven since it's inception, to be a mostly failed material. Great for short-term, not good for long, or permanent use.

If the forum allows attachments, I've attached a couple pics of a junction box on one of my antennas. It now contains two lightning arrestors. If it doesn't pass through the forum, you should receive it direct through the CC. No water, minimal dust, put up in August of 2013.

Kurt

Hi Kurt,
What would you recommend that's easy to apply? I can re-apply it once
in half a year or so. Not really expecting it to last 25 years.
Regards,
Simon

On Tue, Aug 20, 2024 at 9:29?AM Facility 406 via groups.io
<facility_406@...> wrote:

On 8/20/2024 08:56, rfsam wrote:

I was actually thinking about some easy to use spray on UV protection
that I can just use on an amplifier box while it's already mounted on
a mast. Could you recommend any sprays like that? Maybe something that
can be picked up in a local hardware store or Amazon?

I can:

NOT, NOT, NOT!

Recommend the Krylon UV Archival Spray.

As applied, it sucks. Fails almost immediately, relatively speaking,
maybe a month or two.

8 coats?

Still sucks, but fails in a couple years, then the damage to the item
begins.

I have an item in the yard, saw it just yesterday morning.

At least eight coats, noticed fading about two years ago, now, about
four years after putting up, item is unidentifiable. Coating failed
entirely, UV bleached the item bone white, all I bought was some time,
and lost the item.

Maybe a 1/8" thick (when dry) layer would do the job, like when I had to
pour two one gallon cans of Kilz onto a floor before it actually covered
the stain it claimed to- in a single coat, no, wait, three, maybe, they
don't seem to know either.

Krylon may have a purpose, best as I can tell, it's get get money for a
poor product.

Good UV resistant cases have the UV protectant mixed in. They may get
dusty on the surface, but will hold up for 20+ years. You can generally
tell by the uniquely bad chemical smell they give off. Can't describe
it, but once you get a whiff, you won't forget. It's very common in
outdoor weather stations, so if you have a sensor that's holding up, rub
it, then sniff it, see if it smells like toxic waste.

Krylon = NO!

Kurt

On 8/20/2024 08:56, rfsam wrote:

I was actually thinking about some easy to use spray on UV protection
that I can just use on an amplifier box while it's already mounted on
a mast. Could you recommend any sprays like that? Maybe something that
can be picked up in a local hardware store or Amazon?

I can:

NOT, NOT, NOT!

Recommend the Krylon UV Archival Spray.

As applied, it sucks. Fails almost immediately, relatively speaking, maybe a month or two.

8 coats?

Still sucks, but fails in a couple years, then the damage to the item begins.

I have an item in the yard, saw it just yesterday morning.

At least eight coats, noticed fading about two years ago, now, about four years after putting up, item is unidentifiable. Coating failed entirely, UV bleached the item bone white, all I bought was some time, and lost the item.

Maybe a 1/8" thick (when dry) layer would do the job, like when I had to pour two one gallon cans of Kilz onto a floor before it actually covered the stain it claimed to- in a single coat, no, wait, three, maybe, they don't seem to know either.

Krylon may have a purpose, best as I can tell, it's get get money for a poor product.

Good UV resistant cases have the UV protectant mixed in. They may get dusty on the surface, but will hold up for 20+ years. You can generally tell by the uniquely bad chemical smell they give off. Can't describe it, but once you get a whiff, you won't forget. It's very common in outdoor weather stations, so if you have a sensor that's holding up, rub it, then sniff it, see if it smells like toxic waste.

Krylon = NO!

Kurt

Maybe something like
that?
Simon

On Tue, Aug 20, 2024 at 8:57?AM rfsam via groups.io
<1rfsam@...> wrote:

I was actually thinking about some easy to use spray on UV protection
that I can just use on an amplifier box while it's already mounted on
a mast. Could you recommend any sprays like that? Maybe something that
can be picked up in a local hardware store or Amazon?
Thank you,
Simon

On Mon, Aug 19, 2024 at 8:08?PM tardivat via groups.io
<tardivat@...> wrote:

Rather than investing considerable money and effort into some super enclosure its far more effective to coat the loop amplifier PCB in a decent conformal coal lacquer. Conformal coating along with good silicone grease on connections will enable a PCB to survive outdoors with no enclosure.

You can get acrylic or silicone conformal coatings. I prefer the brush on thicker coatings for RF work and it stabilises the rf transformers. The dielectric impact is nothing to worry about at HF.

After this the next best option is fully potting the amplifier with a silicone potting compound designed for electronics.

The other thing that I have used for electronic enclosures is plastic thermos style flasks. They are insulated and have a waterproof screw cap lid. I have had electronics preamps in these enclosures in minus degree temperature for years without issues especially if sealed where holes are made with modern polyurethane and silicone greases.

I was actually thinking about some easy to use spray on UV protection
that I can just use on an amplifier box while it's already mounted on
a mast. Could you recommend any sprays like that? Maybe something that
can be picked up in a local hardware store or Amazon?
Thank you,
Simon

On Mon, Aug 19, 2024 at 8:08?PM tardivat via groups.io
<tardivat@...> wrote:

Rather than investing considerable money and effort into some super enclosure its far more effective to coat the loop amplifier PCB in a decent conformal coal lacquer. Conformal coating along with good silicone grease on connections will enable a PCB to survive outdoors with no enclosure.

You can get acrylic or silicone conformal coatings. I prefer the brush on thicker coatings for RF work and it stabilises the rf transformers. The dielectric impact is nothing to worry about at HF.

After this the next best option is fully potting the amplifier with a silicone potting compound designed for electronics.

The other thing that I have used for electronic enclosures is plastic thermos style flasks. They are insulated and have a waterproof screw cap lid. I have had electronics preamps in these enclosures in minus degree temperature for years without issues especially if sealed where holes are made with modern polyurethane and silicone greases.

A drain hole can be 1mm in diameter and work fine but drilling a smaller hole can lead to drill breakage. Just drill a small hole 1-2mm diameter. Injection moulded plastic boxes have sloping sides ( draft angle) so that the box cleanly exits the moulds. If a box is mounted vertically then drill holes near the "seal". There is no need at all to cover up the hole. But you do need it at the lowest place in the enclosure.

The daily cycle of heating and cooling from day to night causes the air inside the box to heat and cool so air passes into and out of the box every day. When water condenses inside the box it is expelled when the box warms up. A droplet of water can NEVER block the hole.? A filter does not stop the ingress of water, it can only stop insects but you don't get many insects through a 1mm hole, I've? been putting active antennas outside for over 60 years. Initially I used full epoxy encapsulation then switched to an epoxy? dip of the electronics.? Now I use a spray coat of boards, quicker, much cheaper and easy to rework.

In all those years with antennas at many sites I have never lost an antenna through water ingress. But it is very important to stop water entering the coax, the outer screen will corrode causing the crossing conductors to loose contact after a few years. Wrapping the coax and connector with self amalgamating tape that is stretched when applying is a very good sealing method.

Sometimes you can spend 99% of effort? thinking about a 0.01% problem.

73,

Alan G8LCO

Thanks for the reassurance, Simon!

One niggling problem less to fret over :-)

Michael 2E0IHW

On 19/08/2024 17:46, rfsam wrote:

Hi Michael,
Here is a pic of my CCW Experimenters amp. I'd say this vent hole is
about the size of the center pin hole in BNC Female connector. Very
close in diameter.

...

Simon
KM6MUL
On Mon, Aug 19, 2024 at 2:21?AM Michael.2E0IHW via groups.io
<blumu@...> wrote:

Simon, is your hole similar?